A clock is taken as an important element in a microcontroller, and its high precision and wide power supply working range are of great significance to improve the performance of a whole chip. Generally, a Remote Control (RC) clock has a simple structure and is widely applied in an integrated circuit. However, the precision of the RC clock is often limited by the precision of an internal resistor and a capacitor, a power supply and a temperature, and cannot be very high under a full temperature and a full voltage. In an actual application, a deviation to the precision of the chip caused by frequency fluctuation of the clock in a full-temperature range and a full-voltage range is even up to ±2%. Hence, in the related art, large-range fluctuation in an environmental temperature and a power voltage of a place where the clock is located causes the fluctuation of a frequency clock, and thus the precision of the microcontroller has a large deviation.
Concerning the problem of large fluctuation of a clock frequency output by a clock circuit in the related art, an effective solution hasn't been proposed yet till now.